Optical touch detection using input and output beam scanners

A method of detecting a location of at least one object on a touch surface, said method comprising:

• introducing at least two beams of radiation into a panel that defines the touch surface and an opposite surface, said beams propagating by internal reflection between the touch surface and the opposite surface;
• sweeping the beams along the touch surface across a sensing area of the panel;
• receiving the beams at an opposite end of the sensing area;
• directing, synchronously with said sweeping, each of the beams onto a respective common detection point;
• deflecting the beams from said common detection point(s) onto at least one radiation detector;
• and
• identifying said location based on an attenuation of said beams caused by the object touching the touch surface within said sensing area, said attenuation being identifiable from an output signal of the radiation detector.

A method of operating an apparatus for detecting a location of at least one object on a touch surface, said touch surface being part of a panel that defines the touch surface and an opposite surface, said method comprising:

• operating an input scanner arrangement to introduce at least two beams of radiation into the panel for propagation by internal reflection between the touch surface and the opposite surface, and to sweep the beams along the touch surface across a sensing area of the panel;
• operating an output scanner arrangement in synchronization with the input scanner arrangement to
• receive the beams at an opposite end of the sensing area while the beams are swept across the sensing area,
• direct the beams onto a respective common detection point while the beams are swept across the sensing area,
• deflect the beams from the common detection point(s) onto at least one radiation detector;
• and
• identifying said location based on an attenuation of said beams caused by the object touching the touch surface within said sensing area, said attenuation being identifiable from an output signal of the radiation detector.